When will kids, teenagers get vaccinated for COVID-19?

COVID-19 vaccines are in short supply and kids are last in line to get shots. With few exceptions, they’re not expected to get vaccines until next September. And that’s for high schoolers. Young children may not be eligible until next year.

For most infectious diseases, young people are the most vulnerable and the top priority for protection, but not for COVID-19.

Things are out of the ordinary for COVID-19, but not their vaccines, and here’s why:

There are big differences from other infections – kids are not the hardest hit age group and they’re not the “super-spreaders” that they often are with other viral outbreaks. Thus, the Centers for Disease Control and Prevention parked kids in Tier 3 for vaccinations, behind almost everyone else.

New vaccines generally take longer to get to children, often taking years of testing before reaching them.

“All vaccines are tested first in adults for safety, because adults can provide informed consent and give more information about any reactions,” said Bruce Meade, retired Food and Drug Administration regulatory official and vaccine researcher.

He said even if vaccines are intended for use in infants and children, the first step is to accumulate safety data in adults before moving to younger age groups.

“Even older age groups of kids can understand the risks and benefits of a (vaccine) trial and provide more input about reactions,” said Meade.

The downward age progression is done cautiously, as the risks and benefits of a vaccine can be different for each age group.

The SARS-CoV-2 Infections and the immune responses are remarkably different for children, compared to adults — especially the elderly — so health officials want to ensure that COVID-19 vaccines are safe and that they work in younger ages.

“We’re in the process of starting clinical trials in what we call age de-escalation, where you do a clinical trial with people 16 to 12, then 12 to 9, then 9 to 6,” said Dr. Anthony Fauci, the nation’s leading infectious disease expert, in an interview with ProPublica.

That de-escalation is not happening quickly enough for some pediatricians.

“If we do not add children to these research trials very soon, there will be a significant delay in when children are able to access potentially life-saving vaccines. This is unconscionable.,” said Dr. Sally Goza, president of the American Academy of Pediatrics, in a press release in November.

The AAP’s pleas for urgency for testing vaccines for kids haven’t changed, especially with more than 63 million doses of the Pfizer and Moderna vaccines administered to adults in the United States by Feb. 21.

The AAP sent a letter to federal officials at the FDA and Health and Human Services expressing their concerns about the delay in protecting children, as they are also susceptible of COVID-19.

As of Feb. 1, more than 3 million children have been infected with coronavirus, and though rare, severe complications can occur, including the multisystem inflammatory syndrome in children.

Vaccines in pipeline for kids

“The pandemic has been very impactful for adolescents,” said Dr. Nicola Klein, vaccine researcher and director of Kaiser Permanente Vaccine Study Center in Oakland. “Some (teens) participate in the trial because of the impacts on their lives and some want to help for the common good.”

Klein, a pediatrician, is one of the lead investigators for the Pfizer BioNTech COVID-19 vaccine trial in adolescents, 12 to 17, which completed enrollment in mid-January.

She said, “It’s important that we move trials into children,” and that the adolescent trial proceeded very much like other trials in that age group, without any surprises. The results are not yet available.

Pfizer vaccine is one of the mRNA vaccines that received Emergency Use Authorization from the FDA in December. This vaccine is the first to be studied in youth, and nearly 3,000 adolescents have completed vaccination nationwide. The company plans to start a trial in younger children in the spring.

Moderna’s mRNA vaccine has an EUA for adults 18 and older. The company is currently studying the two-dose regimen of their vaccine in adolescents, 12-17.

Johnson & Johnson submitted data to support an EUA for their COVID-19 vaccine in adults, which is currently undergoing FDA review and will be discussed publicly on Feb. 26. They plan to start trials in adolescents in a few weeks.

In England, Oxford-AstraZeneca began trials last week in children as young as 6, the youngest ages to receive COVID-19 vaccines. This product is approved in the United Kingdom and several other countries, but data have not been submitted to the FDA.

Vaccine trials for the youngest ages of infants, toddlers and preschoolers are not yet planned.

Studying more vaccine candidates in younger age groups will likely increase the pool of available vaccines, but performing the trials takes time.

Phases to study new vaccines

Before use in humans, vaccines undergo pre-clinical evaluations. First is laboratory research — think Petri dishes and microscopes — where scientists study a microbe to understand how it causes infection. Generally, the next step is evaluating the germ and the immune response in animals.

Then human testing happens in four clinical phases.

Phase 1 is safety testing, usually in 20 to fewer than 100 healthy adults. Phase 2 monitors safety and immunogenicity (the ability to elicit an immune response) in hundreds of volunteers.

Phase 3 trials’ main goal is to test the efficacy of the vaccine, that is how well it protects against infection or disease. These trials frequently enroll thousands of subjects, and also gathers additional safety and immunogenicity data.

For the Pfizer and Moderna vaccines, their efficacy trials combined included more than 70,000 participants, and both demonstrated more than 94% efficacy.

Phase 4 is post-approval monitoring for safety problems such as rare adverse events, which may not be seen until the vaccine is given to millions of people. Pfizer and Moderna have committed to perform active monitoring of study volunteers.

In addition, the CDC and FDA maintain the Vaccine Adverse Event Reporting System for collecting safety reports about all vaccines available to the public.

Progressing through these phases generally takes months to years. Although it seemed to happen much more quickly for the COVID-19 vaccines, decades of research with related vaccines, including for SARS in 2002 and MERS in 2012, laid the groundwork for the rapid availability of COVID-19 vaccines.

Children are rarely, if ever, enrolled in Phase 1 trials. They can be included in Phase 2 and 3 trials, as needed for approval of a product in their age group.

For COVID-19 vaccines, Phase 3 efficacy trials in children and teens are not necessary for the Pfizer or Moderna vaccine. Instead, the antibody levels in vaccinated kids will be compared with those from the adult trial.

Vaccination of Stanislaus County kids

“We haven’t heard of any plans to vaccinate children yet. We are still following the guidelines from state as far as vaccine distribution goes,” said Kamlesh Kaur, Stanislaus County public health spokesperson, in an email last Thursday.

California Department of Public Health vaccine prioritization considers age and risk. Beginning March 15, teens 16-19 with certain underlying conditions will be eligible for vaccinations.

Fauci delayed his anticipated timeline for COVID-19 vaccines to get to children as young as age 5 from September until 2022, at a White House briefing last Friday,

Although there is much discussion among parents and health officials if COVID-19 vaccines will be mandatory for children to go to school, it’s not likely for the 2021-22 school year as there probably won’t be enough vaccines for school-age kids by then.

The CDC guidance for safe re-opening of schools does not require vaccination of school personnel or students.

“For the world to move forward from this pandemic, we need to immunize our kids, “ said Dr. Klein.

This story was produced with financial support from The Stanislaus County Office of Education and the Stanislaus Community Foundation, along with the GroundTruth Project’s Report for America initiative. The Modesto Bee maintains full editorial control of this work.

To help fund The Bee’s children’s health and economic development reporters with Report for America, go to bitly.com/ModbeeRFA